Apparatus for use in the visual inspection of sheet metal



April 4, 1950 E. D. MARTIN 2,502,469

APPARATUS FOR USE IN THE VISUAL msmc'rrox 0F SHEET mmmu 4 Sheets-Sheet 1 Filed Sept. 19, 1945 April 4, 1950 E. D. MARTIN 2,502,469

APPARATUS FOR USE IN THE VISUAL INSPECTION OF SHEET MATERIAL Filed Sept. 19, 1945 4' Sheets-Sheet 2 April 4, 1950 E. D. MARTIN 2,502,469

APPARATUS FOR USE IN THE VISUAL INSPECTION OF SHEET MATERIAL Filed Sept. 19, 1945 4 Sheets-Sheet s April 4, 1950 E. D. MARTIN 2,502,469

APPARATUS FOR USE IN THE VISUAL INSPECTION OF SHEET MATERIAL Filed Sept. 19, 194-5 4 Sheets-Sheet 4 asoaaco to a reciprocating device I8. In the form here illustrated the arm contains a slot as within whichlscarriedapinllsecuredtoarodli. This rod is automatically actuated in any suitable manner synchronously with the sheet feeding mechanism so that the plate 08 is tilted periodically immediately after a sheet has been supplied thereto. The compression spring 42, secured on the end of the rod I, may be relied upon for returning the plate to its original position. If desired, however,the rod may be positively fed in each direction.

The plate is, of course, provided with slots ll through which the wires 20 pass. v

The lower ends of the wires 2! are secured in brackets I l best shown in Fig. 2. The wires guide the sheets II, dropping from the plate 05, into enga ement with the surface of the steel drum l2 and the driven belt 83. Thisbelt, and the other belts, are preferably of a fabric material such as canvas. The sheets are carried on the belt 3, as illustrated in Fig. 1, to the separator ll. mechanical means, not here shown and not part of the present invention, through the medium of the button 48. This button "operates an electrical system, including a time delay switch, such that the operator may push the button at any time between the time one sheet contacts the plate and the time the next sheet contacts the plate. with the result that the button, when pressed, will elevate the separator 45 at the proper time and thus bring the discarded sheet onto the belt 41. In normal operation the separator Iii is in the position shown in Fig. 1 and the sheets pass along the'belts 48 and 48 to a pile where they are stacked and weighed. It will be observed that normally 2 or 3 sheets will be spaced along the belt I, but that operation of the push button It affects the separator 45 only at the appropriate time and for the appropriate interval, discarding the sheet which has last been inspected by the operator before she pushes the button.

Inasmuch as the sheets employed may be of different sizes, it is preferred to provide means for adjusting the level of the feeding system. Such a means is best illustrated in Fig. 3 and includes bridge frames ill and ti located respectively at the rear and at the front of the device. 'lhese frames carry the rollers 21 and 36 and the idler roller 52, and are adjustable upwardly and downwardly by synchronous movement of the screw posts 53, I4, I, and 50. The posts may be turned synchronously by any suitable mechanism as indicated at 51.

The operation 01' the device should be obvious from the foregoing explanation. The frames ll and ii are first adjusted to the proper height so that the braking rolls II will retain their effect upon the plate until it is substantially in viewing position. Individual plates are then fed at predetermined intervals seriatim through the elevating mechanism over the drum is and then dropped into viewing position before the mirrors l2. Ordinarily, sheets are fed at the rate of 54 to 90 per minute, depending upon the ability of the operator and the size of the sheet. The sheets impinge upon the plate I, and usually bounce a very small fraction of an inch. They are held in position only long enough to produce a retained image on the retina of the eye of the observer. In actual practice, it has been found that the operator will view one side of the sheet in one mirror and then turn her eyes and view the other side of the sheet in the other mirror.

The separator is actuated by any suitable;

The sheet should, therefore, be stopped long enough to permit retention of two images and the intervening movement of the eyes of the operator. The plate 85 is then automatically tipped to drop thesheet between the belt 83 and the drum 2. Any sheet which should be discarded is sent to the discard file by pushing the button 48 which operates the separator Iii by delayed action so that the appropriate sheet is discarded when it reaches the separator.

The foregoing detailed description has been given for clearness of understanding only, and no unnecessary limitations should be understood therefrom.

What I claim as new, and desire to secure by Letters Patent. is:

1. Apparatus for use in the inspection of metal sheets, comprising: a viewing station having an entrance at the top and an exit at the bottom, said station being arranged for receiving metal sheets with an edge disposed toward a predetermined viewing position; feeding means on the apparatus for moving sheets toward the viewing station, said means terminating directly above said viewing'station and having means for dropping sheets at predetermined intervals in a vertical position into the viewing station; means in the viewing station for simultaneously presenting images of the two faces of a sheet in said station to an observer at the viewing position; a stop element at the bottom of the viewing station for stopping a sheet dropped by said feeding device, said element being movable between a stop position and a release position; stop actuating means for moving said stop element to its release position at said predetermined intervals to release a sheet for removal by gravity from said viewing station; and means for returning saids elementtoits stop position.

2. Apparatus as set forth in claim 1 wherein a plurality of pairs of spaced guide wires are provided tor receiving the sheets from the feeding device and guiding themto the stop element.

3. Apparatus for use in the visual inspection of sheet'metal, comprising: a viewing station; means for feeding sheets seriatim at predetermined intervals to said viewing station; means adjacent said viewing station for inspecting both sides of a sheet at the viewing station simultaneously from a predetermined position; a stop element at the viewing station cooperating with the feeding means to receive each sheet as it comes from the feeding means and retain it momentarily in the viewing station; and means to move the stop element to release the sheet for removal from the viewing station.

4. A device as set forth in claim 3 in which means are provided at the viewing station for arranging each sheet in vertical position therein.

5. Apparatus for use in the visual inspection of sheet metal, comprising: a viewing station; continuous means for feeding sheets seriatim at predetermined :ntervals to said viewing station; means adjacent said viewing station for inspecting both sides -of a sheet in the viewing station simultaneously from a predetermined pomtion; a plurality of wires extending through the viewing station positioned to guide each sheet into a vertical position in the viewing station as it comes from the feeding means; a stop element at the viewing station to receive each sheet in said vertical position and retain it momentarily in the viewing station; and means to move the stop element to release the sheet for removal from the viewing station.

6. Apparatus for use in the visual inspection of sheet metal, comprising: a viewing station arranged to receive a metal sheet in upright position; means for feeding sheets seriatim at predetermined intervals downwardly into an upright position in said viewing station; means adjacent said viewing station for inspecting both sides of a sheet in the viewing station simultaneously from a predetermined position; a stop element including a movable plate located at the .portion of the viewing station directly opposite said feeding means to receive each sheet from the feedin means and retain it momentarily in the viewing station; and means for moving the plate at said predetermined intervals to release the sheet for removal by gravity from the viewing station.

7. Apparatus according to claim 6 in which the movable plate is pivotable about one of its edge portions.

8. Apparatus for use in the visual inspection of sheet metal, comprising: a viewing station having an entrance side and an exit side, said station being arranged to receive metal sheets with an edge disposed toward a predetermined viewing position; feeding means on the apparatus for moving the sheets toward the entrance side of the viewing station and feeding them seriatim at predetermined intervals into said viewing station; means adjacent the viewing station for simultaneously inspecting both sides of a sheet in said station from the viewing position; a stop element at the exit side of the viewing station to receive each sheet as it comes from the feeding means and retain itlmomentarily in the viewing station; means for moving said element between a stop position and a release position; and means for removing a sheet when the stop element is at the release position.

'9. Apparatus for use in the visuaLinspection of sheet metal, comprising: a viewing station having an entrance side at its top and an exit side at its bottom, said station being arranged to receive metal sheets in an upright position with an edge disposed toward a predetermined.

viewing position; feeding means on the apparatus for moving sheets toward the entrance side of the viewing station and feeding them seriatim at predetermined intervals into said viewing station; means adjacent the viewing station for simultaneously inspecting both sides of a sheet in said station from the viewing position; a stop element at the exit side of the viewing station to receive each sheet as it comes from the feeding means and retain it momentarily in the viewing station; and means for moving said element between a stop position and a release position to permit a sheet to drop from the viewing station by gravity.

10. Apparatus as set forth in claim 9 wherein the viewing station is provided with a plurality of pairs of spaced guide wires to guide the sheets from the feeding means to the stop element and retain them in a vertical position for inspection.

11. Apparatus for use in the visual inspection of sheet meal, comprising: a viewing station, continuous means for feeding sheets seriatim at predetermined intervals to said viewing station; means adjacent said viewing station for inspecting both sides of a sheet in the viewing station simultaneously from a predetermined position; guide means in the viewing station to guide sheets from the feeding means into a vertical viewing position; a stop element at the viewing station cooperating with the feeding means to receive each sheet as it comes from the feeding means and retain it momentarily in the viewing station;

and means to move the stop element to release the sheet for removal by gravity from the viewing station.

EDWIN D. MARTIN.

REFERENCES CITED The following references are of record in the 

